DEVICE AND METHOD FOR LIMITING THE SWITCH-ON CURRENT WHEN OPERATING A CAPACITIVE LOAD ON A THREE-PHASE INVERTER

Device (10) for limiting the inrush current (I) when operating a capacitive load (34) on a three-phase inverter (14), comprising a three-phase inverter (14) with first, second and third load outputs (28±, 28², 28³), which are each connectable through corresponding control of associated switching means (24±, 24², 24³, 26±, 26², 26³) to a first direct voltage potential (+DC) or to a second direct voltage potential (-DC) deviating from the first direct voltage potential (+DC). The capacitive load (34) is in a precharging mode through control of the switching means (24±, 26³) in a current limiting branch (52) via the first load output (28±) by means of an interposed current limiting element (54), in particular a current limiting resistor (56) or a current limiting inductance, connected to the first direct voltage potential (+DC) and via the third load output (28³) to the second direct voltage potential (-DC), so that an inrush current (I) occurring between the three-phase inverter (14) and the capacitive load (34) is limited in magnitude. In a normal operating mode following the precharging mode, the capacitive load (34) is connected through control of the switching means (24², 26³) in a power supply branch via the second load output (28²) directly to the first direct voltage potential (+DC) and via the third load output (28³) to the second direct voltage potential (-DC).